rs1244655820

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000263.4(NAGLU):c.1597C>T(p.Arg533Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,976 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

NAGLU
NM_000263.4 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 1.12

Variant links:

Genes affected

NAGLU (HGNC:7632): (N-acetyl-alpha-glucosaminidase) This gene encodes an enzyme that degrades heparan sulfate by hydrolysis of terminal N-acetyl-D-glucosamine residues in N-acetyl-alpha-D-glucosaminides. Defects in this gene are the cause of mucopolysaccharidosis type IIIB (MPS-IIIB), also known as Sanfilippo syndrome B. This disease is characterized by the lysosomal accumulation and urinary excretion of heparan sulfate. [provided by RefSeq, Jul 2008]

NAGLU links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 69 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 17-42543603-C-T is Pathogenic according to our data. Variant chr17-42543603-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 495784.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NAGLU	NM_000263.4 linkuse as main transcript	c.1597C>T	p.Arg533Ter	stop_gained	6/6	ENST00000225927.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NAGLU	ENST00000225927.7 linkuse as main transcript	c.1597C>T	p.Arg533Ter	stop_gained	6/6	1	NM_000263.4	P1
NAGLU	ENST00000591587.1 linkuse as main transcript	c.*566C>T		3_prime_UTR_variant	4/4	5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152262

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1460714

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726658

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152262

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74402

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Mucopolysaccharidosis, MPS-III-B

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 28, 2017	The NAGLU c.1597C>T (p.Arg533Ter) variant is a stop-gained variant that is predicted to result in premature termination of the protein. The p.Arg533Ter variant has been reported in one study in which it was found in two individuals with mucopolysaccharidosis type III, specifically type IIIB, including in one who carried the variant in a homozygous state and one who carried the variant in a compound heterozygous state (Mangas et al. 2008). The p.Arg533Ter variant was absent from 50 unrelated controls and is not found in the 1000 Genomes Project, the Exome Sequencing Project, or the Exome Aggregation Consortium in a region of good sequence coverage so the variant is presumed to be rare. Characterization of cell lines derived from the two patients showed significantly reduced mRNA levels and enzymatic activity (Mangas et al. 2008). Based on the evidence and the potential impact of stop-gained variants, the p.Arg533Ter variant is classified as likely pathogenic for mucopolysaccharidosis, type III. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, no assertion criteria provided	curation	Department Of Genetics, Sultan Qaboos University Hospital, Sultan Qaboos University	Dec 30, 2017	- -

Inborn genetic diseases

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 27, 2021

The c.1597C>T (p.R533*) alteration, located in exon 6 (coding exon 6) of the NAGLU gene, consists of a C to T substitution at nucleotide position 1597. This changes the amino acid from an arginine (R) to a stop codon at amino acid position 533. This alteration occurs at the 3' terminus of the NAGLU gene, is not expected to trigger nonsense-mediated mRNA decay, and impacts the last 28% (210/743 amino acids) of the protein. Premature stop codons are typically deleterious in nature and the impacted region is critical for protein function (Ambry internal data). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This mutation has been reported in the homozygous and compound heterozygous states in patients with biochemically confirmed mucopolysaccharidosis type III. Patient cell lines demonstrated significantly decreased levels of mRNA and enzymatic activity (Mangas, 2008). Based on the available evidence, this alteration is classified as pathogenic. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Jul 01, 2019

- -

Mucopolysaccharidosis, MPS-III-B;C5569050:Charcot-Marie-Tooth disease axonal type 2V

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 25, 2023

This sequence change creates a premature translational stop signal (p.Arg533*) in the NAGLU gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 211 amino acid(s) of the NAGLU protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with mucopolysaccharidosis type III (PMID: 18218046). ClinVar contains an entry for this variant (Variation ID: 495784). For these reasons, this variant has been classified as Pathogenic. -

Sanfilippo syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Dec 23, 2016

Variant summary: The NAGLU c.1597C>T (p.Arg533*) variant results in a premature termination codon, predicted to cause a truncated or absent NAGLU protein due to nonsense mediated decay (NMD), which are commonly known mechanisms for disease. Functional analysis shows that this variant escapes NMD (Mangas_2008). Thus, based on its location and effect, it is expected to delete a substantial part of Alpha-N-acetylglucosaminidase, C-terminal domain (residue 474 733) (InterPro). Truncations downstream of this position (e.g. p.Arg626Ter, c.1944dupG, etc.) have been reported in MPS IIIB patients and classified as pathogenic by the labs in ClinVar. This variant is absent in 114224 control chromosomes from ExAC. In literature, this variant has been reported in two Portuguese MPS IIIB patients: one patient with severe disease was homozygous for the variant and other patient with mild disease was compound heterozygous for this variant and R643C (Mangas_2008). Functional analysis using patient cells from the homozygote showed null enzymatic activity. Taken together, this variant is classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.66

BayesDel_noAF

Pathogenic

0.49

Cadd

Pathogenic

Dann

Uncertain

1.0

Eigen

Uncertain

0.39

Eigen_PC

Benign

0.15

FATHMM_MKL

Benign

0.72

MutationTaster

Benign

1.0

Vest4

0.58

GERP RS

3.7

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over